Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Large Casimir cavity

  1. Nov 4, 2015 #1
    Assume that one builds a Casimir cavity in the traditional manner, with closely spaced walls. We know the Casimir Effect becomes more pronounced the closer the walls are spaced.

    Now, if one were to build six such Casimir cavities, and assemble them into a box, would the same effect be noticed within the interior space within that box as is noticed between the dual-walls of each individual Casimir cavity?

    Would the walls of each individual Casimir cavity making up this box need to be insulated from each other or prevented from touching in some way (ie: individual Casimir cavities making up the box cannot touch each other), since the Casimir Effect ends when the two walls touch in a traditionally-built Casimir cavity?

    If such is the case, would an insulating layer of thin plastic between the walls of the Casimir cavities (and between each individual Casimir cavity making up the walls of the box) suffice as a spacer, or would that somehow negate the Casimir effect?
    Last edited: Nov 4, 2015
  2. jcsd
  3. Nov 6, 2015 #2

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    1. The casimir effect is only between the plates
    2. No - a vacuum is usual. You'd need some way to keep the plates apart though.
    3. I dont think it has to be an insulator... so long as it does not fill the gap.
    What do you have in mind?
  4. Nov 6, 2015 #3
    But if the virtual particles are being excluded from the gap between the walls and are thus impinging more "heavily" upon the exterior of the walls (the cause of the Casimir Effect), and you put walls that are excluding these virtual particles into the shape of a box, wouldn't the interior of that box also have the virtual particles excluded? How would they find their way in there if they're excluded at the perimeter?
    Last edited: Nov 6, 2015
  5. Nov 6, 2015 #4


    User Avatar

    Staff: Mentor

    You need to learn more about the origin of the Casimir effect. Using the picture of virtual particles, it is only in the narrow cavity formed by two near plates that some virtual photons cannot appear, as the modes they correspond to have a wavelength greater than twice the distance between the plates. Within the box, you would have the same effect as two plates that are far apart.

    Also, you should know that virtual particles don't actually exist. In a sense, they correspond to a mathematical tool. You will find many posts on PF discussing this.
  6. Nov 6, 2015 #5
    Ok, throwing aside the naive "particle interpretation of Quantum Field Theory" (this was supposed to be a B-level question, after all), and forgetting for the moment that Chalmers University researchers in 2011 concretized microwave photons from the ZPE field using Dynamical Casimir Effect (thereby proving the existence of these virtual particles you say "don't actually exist"), and setting aside the fact that virtual particles play a role in the Coulomb force, magnetic fields, electromagnetic induction, strong and weak nuclear force, spontaneous emission, the Casimir effect and van der Waals force, vacuum polarization, the Lamb shift, Hawking radiation and near-field effects... but if you say they're just a "mathematical tool", we'll go with that. Heh.

    (Yes, I'm aware that in Quantum Field Theory, everything is a wave. What we classify as "real particles" are waves with a relatively stable field waveform, whereas "virtual particles" are more an unstable pulse in the Quantum Vacuum Zero Point Energy field.)

    Now substituting quantum field theory, which states that Quantum Vacuum Zero Point Energy field density is excluded in the space between the walls via exclusion of wavelengths greater than twice the distance between the plates, creating less of a radiation pressure effect in that space, thus pushing the two plates together...

    If there were a "Casimir box" such that each of the six walls of the "Casimir box" were comprised of traditional Casimir cavity walls, and if the opposing inner walls of each Casimir cavity comprising each wall were (electrically?) connected such that vacuum fluctuations couldn't be induced on the opposite side of that wall (because remember, we're talking about an electromagnetic field), thus canceling out any ZPE field not only in the Casimir cavities making up each wall of this "Casimir box", but in the interior space in that "Casimir box"... would that work?

    I'm trying to conceive of a geometry whereby a large Casimir cavity could be constructed and still exclude the wave modes that are excluded by a traditional Casimir cavity.
    Last edited: Nov 7, 2015
  7. Nov 6, 2015 #6

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    By "would it work", you mean, "would this create a large regeon inside the box that would amount to a strong casimir cavity" then the answer is "no". The box described would have the same modes as if its walls were not casimir plates... if Ive followed the description correctly.
    It sounds like you are looking for a way to generate energy from the "zpe field".
    See: https://van.physics.illinois.edu/qa/listing.php?id=1256

    Don't be mislead by the way virtual particles are talked about in pop sci and in the literature.
    Last edited: Nov 7, 2015
  8. Nov 7, 2015 #7
    No, not from the ZPE field, per se. And not a "strong" Casimir effect, just the same effect as is seen between the walls of each Casimir cavity making up the "Casimir box". I'd thought that by electrically "shorting" opposing inner walls, no field fluctuations could be induced inside the inner walls, thus the reduced field density seen between the walls of the Casimir cavities making up the walls of the "Casimir box" would also be experienced in the interior of the "Casimir box".

    A thing to note is that the integral of the perturbation of the quantum vacuum around the nucleus for a given atomic number Z and quantum number n is exactly equal to the energy level of the electron in that state. The energy level of the electron is a function of its potential energy and kinetic energy. Does this mean that the energy of the quantum vacuum integral needs to be added to the treatment of the captured electron as another potential function, or is the energy of the quantum vacuum somehow responsible for establishing the energy level of the "orbiting" electron? The only view to take that adheres to the observations would be the latter perspective, as the former perspective would make predictions that do not agree with observation.

    Boyer showed in 1975 that the hydrogen atom in its ground state would be in a state of equilibrium between Larmor radiation and absorption of QVZPE at the correct radius for a classical Rutherford hydrogen atom.

    Given that we now know that the quantum vacuum imparts a minimum energy level to the electrons in their standing wave Bohr "orbits" about the nucleus, preventing the electron from crashing into the proton by setting the "ground state" number of De Broglie waves the electron can have in its standing wave orbit... I'm exploring what would happen if we could crash the electron into the proton by putting matter into a reduced ZPE field environment. Forced electron capture decay of any element we wanted, to be sure, but would it completely "unwind" matter, given that we now know the ZPE field underpins the stability of matter?
    Last edited: Nov 7, 2015
  9. Nov 7, 2015 #8

    Simon Bridge

    User Avatar
    Science Advisor
    Homework Helper

    I see, the idea is that the atomic ground state inside a casimir cavity would be lower than one outside, so passing an atom into such a cavity could get it to decay further. That correct?
  10. Nov 7, 2015 #9
    Exactly. And if we were (somehow) able to completely (or sufficiently) negate the ZPE field density inside that Casimir cavity, whether matter would electron capture decay back up the Periodic Table until we hit hydrogen, which would electron capture decay into neutrons, gamma energy photons, and anti-neutrinos. In short, a matter destructor.
  11. Nov 8, 2015 #10


    Staff: Mentor

    Thread closed. Please review the forum rules regarding personal speculation.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook